Pigmented waxes and method of preparing same



to The B. F. Goodrich Company, New York, N; Y., a corporation of NewYo'rl' Nwawsg, nppuemanruemrass;

S rihlllo.;359;223fwo p fil -term fit w t n b ent August has. beendisclaimed. and dedicated. to the in -1 This invention relates topigmented" compositions. and more particularly relates to the productionof 'pigmente'd compositionsofmattersuitable for the coloring of plastics generally and" specifically inthe present application to thepigmentation of" one" of the classes of pl'astics, namely. waxes,disclosed in my: prior application Serial No; 1025;423; filed August 3,1949; United1states-Patent No; 2,649'382, issued August 18; 1953, ofwhich this present-applicationis'a continuation-impart; g p

The production of plastic masses containing dispersed pigment forincorporation into large batches for" colormg purposes is no't' broadlynew. such dispersions are known in the industry: as color masterbatches. In the production, ofwax. color master batches heretoforeittlias lieeuinece'ssary to submit pigmentand 'wax. toprolonged and;expensive. mechanicall working; .in equipment capable," of; exerting-ahigh shearing; stresses inorder. to' achieve a dispersion of pigment. inwax-.05 moderately satisfactory qualityl v Insuchprior. operations themillmg times are considerable, the power requirements for such equipmentvery. high, the constant attendance of skilled labor is. required, andthe. degreeot dispersion obtained. leaves much-to; be desired. whenavery' fine dgreeoffdispersionis required v discovered thatwax' colormaster batches of entremely. quality. can be preparedeinr am efiicientmanner with simple inexpensive milling, f: pigment and wax by the use ofa novel and special type of liquid grinding medium, whicli later can beeasily removed from thklniilfid batch, and evenreused, if desired,, fornew ba'tche's; After the removal of the liquid grinding nfe ice IPatented? 4,;

ttie'miktureof wax,pigmentandliquidgrindihgmediumi the mill closed andallowed to grind 'tlie itiiktiire'gwitli out necessity foranyat'tendant;untilia dispersionofjpigmanna-Quite desired degree' is-iolitaiiie'dl 1 1l some of the solid organic waxes, but by no meansall' such. waxes,whic'lil come within that term a'sin this applica'tion employed whichincludes both natural? wares diiun"froni 'tlieImilled batch,. the disersedP igment-im We); ifs driei', the dried, wax. master. colon batchbeing normally in a free-flowing particulateform,whichtis soft intexture. I k I p wax mastercolorsbatches producedin; the novel process:above recited are. stable, uniform andiree from agglomerates, have-ahigh chromaticity, and,;wh'enused to-colorrotherl masses,.. makeavailablethe full strength ot'thepigment-employed; p

Furtl ier objects of this invention will-beapparentfromthedetailedspecifications which'follo-w; In, practicing; theqinventionof this application; I- place in a ball, pebble or other colloidal milla mixture con+ sisting essentially; of; thewax to I be pigmented; the:specific pigment, tandithe-novel liquid grindingmediunr com prisingwaterr-and a= liquid organic solvent: for; the Wax to be=pigmentedcharacterized additionallyby its, water+ miscibility; Preferably,-. boththe wax: and the: pigment are iii-particulate form The-organicsolveneand water are present in thesnoveltliquids grinding-:mediumimsuchproportions that the liquidigrindingiz medium: does not d-issolv'er asubstantiali amount oh the: wax' ancl does not cause substantial.agglomeration; of? the? wax. The: balls. or pebbles or other solidgrinding elements are added to and synthetic waxes; The-commonjsolidorganic axes: of natural originfl a're beeswax, .Chiiie'se' waXQcahdel'la; wax, c rnauba: wax; Ja an wax, montan wax, oz'dcente, Wax, cere'sinw'ax, paranm wax; sperma'c'etit w'ax efc. The synthetic solid organicwaxesare commercially avail;

able in'great numbers. They include the high molec ular 7 weight, fattyacids andv alcohols, and" admixtures. thereof, occurring in natuiallwaxes, such asv .lauric"acid; l palinitic acid,. ccrotic acid, montanicI acid; meliss'icacid, ,cetyl" al cohol, .octadecyl alcohol,- cerylalcohol}, melissyl alcohol} pentacosane, hentriaconta ne, ,andhighermolecular weight parafii ns. of the. generic 'formulaCnH1i+z,.suchas.oz;ocerite, ceresimparaffin etc. They. also includethesolid organie acids, such as stearic acid andlthei soaps oflthe. fattyacids, such as Opalwax; and also halogenatedard matic compounds,ofwhichchlorinateddiphenyls (Arochloryand chlorinated naphthalenes(Halowax) are-i1; lustrative; The solid organic Waxes. hereinabovelistedare notlimitative of the solid organicwaxes suita-ble for thepurposesofi this lHVGDtiOILwbUC-BI'B here given-by way ofeqgamplesonly.V p ,As-pigment, one may; employ any oftheasolid colorants waxes. Theseinclude the inorganic prime pigments;

7 organic prime pigments,. various inertor extender Ipig;

ments, metallic pigments and the various=-finelyi divided carbon,blacks, including bone and: gas blacks, suchasdiselosed-inMattiellosProtective and Decorative Goat? ings, volume 2;, chapter 1(1942 01* the Journal-of thef Societyof- Dyers and Colorists, volume 61-(-307);;D6e cember 1945. r

As aniessential: feature of the invention; the solici organicwax andpigment are -mix'ed-with a -liquid=grinding medium comprising water anda liquid organie watef miscible solvent for-'thewax employed. ItiSfimpOItaIit that the mixture of water and solvent be present in. suchproportions in the liquid: grinding medium: that, during the time ofprocessing; themixtureof liquid: organic sol vent andwater does" notsubstantially diss'olv'efthesolid organic-wax or substantially'cause itto gel 'or -fagglom erate; To accurately find the-pointatiwhich'theliquid organic solvent and water liquid grin'dingimedi-umbecomes-substantially a non-solventfor the sol-id organic' w'axg aseries' A small amount of the solid organic wax is thenadded to eachbottle, preferably in the physical form in which it is to be used and inan amount of about 1 part of solid organic wax to 4 parts of liquidmedium. Theimixture is well-agitated and the solid organic wax is thenpermitted to settle. 1 One may note that in one 'or more of the bottlesthe solid organic wax either goes completely into solution or clumps oragglomerates into a more or less translucent, gel-likeimass. Itrwillalso be noted that in the remaining bottles, the -wax retains a discreteparticle appearance. While these effects can generallybe observed ahnostimmediately, it is better to permit about 4 hours of contact beforecomparisons are made and still more preferably one may-allow as muchtime for contact as is to be given during the actual pigment dispersionoperation.

The action of the mixture of water and liquid organic solvent onthesolid organic wax when it is less drastic than that which causes agellingand agglomeration of the solid organic wax and yet containssufi'icient solvent to make the solid organic wax receptive to pigmentdispersion' can best be termed a pigment receptive action" on the wax. 1

The most desirable and optimum water-organic solvent liquid grindingmedium has been found to be the one having that proportion of water justsufficient to prevent the above-mentioned extensive solvent action, andyet have enough solvent present to attack the solid organic wax andmakeit receptive to the entrance and dispersion of pigment. It should beclearly understood, however, that for operability there is no precisepercentage of solvent in water or precise point where the liquid mediumimparts the receptive quality to the solid organic wax but, rather, arange which may vary from about 2 or 3 percent-in the case of particularsolvents and particular solid organic waxesto as much as about 90% withother solvents and solid organic waxes. The indication that the amountof solvent is approximately below that which results in gelling oragglomeration is intended to cover that range where the pigmentreceptive action on the solid organic wax takes place.

The amount of liquid grinding medium comprising liquid organic solventand water, used in the process, is selected by the operator to besufiicient to give fluidity to the solids in the particular mill used inthe process. A mill with flint pebbles, for example, will generallyrequire more liquid grinding medium than one using steel balls. It is,of course, obvious that one may, if so desired, use other types of millsfor the grinding operation.

Such liquid organic water-miscible solvents'which will solubilize thesolid organic waxes include the alcohols, as, for example, methyl,ethyl, iso-propyl alcohol, diacetone alcohol, etc.; dioxane; the glycolethers as, for example, the Cellosolves and the Carbitols; the esterssuch as the Cellosolve acetates and methyl or ethyl lactate; the ketonessuch as acetone, methyl-ethyl ketone; and other solvents or mixture ofsolvents for the solid organic waxes well-known to the art.

For a better understanding of the invention, the following examples aregiven, it being clearly understood that these are merely by way ofillustration and not to be considered limitative of the invention.Reference to the pighnents employed utilize the generally accepted tradename. The letter M with figure and page number following the name refersto the figures and pages in volume 5 of J. J. Mattiellos Protective andDecorative Coatings which gives the chemical composition. Thedesignation C. I. refers to the well-known Colour Index published by theSociety of Dyers &'Colourists.

Unless otherwise noted, all percentages are to be considered as being ona weight basis.

* Example 1 Acne-gallon porcelain pebble mill is charged with 150 gramsof Pyrazolone Red Toner (M: Fig. 71, page 402) and 1100 grams of aliquid grinding medium comprising 733 gramsof water and360 grams of"acetone (33.3 solvent). Tnis is well mixed and tothe mixture is thenadded 300 grams of powdered paraffin. About 7 lbs. of #00 French flintpebbles are added and milling is carried out for approximately 45 hours.The mill is then discharged and rinsed out with water. The product andwash liquid are collected and filtered. The filter cake is finallywashed, dried and pulverized. One obtains about 435 grams of a brightred powder paraflin product which is excellently suited for themanufacture of colored candles. 1

ExampleZ A one-gallonporcelain-pebble mill is charged with grams ofDianisidine Blue Toner (M; Fig. 43, page 388) and 1600 grams of a liquidgrinding medium consisting of 50% denatured ethanol and 50% water. Thisis mixed well and to the mixture is added 200 grams. of Stearic AcidTriple Pressed Pearls. About 7 lbs. of #00 French flint pebbles areadded. After milling for about 45 hours, the mill is discharged andrinsed out with water. After filtration and washing the filter cake isdried at F., which is below the melting point of stearic acid, and thedried product is then pulverized. One ohtains 294 grams of deep bluelumps which may be comminuted and screened to any desirable size, thusforming a non-dusting particle which disperses readily into rubber.

In another operation, Fanchon Maroon Toner (M: Fig. 105, page 419) issubstituted as a pigment. The resulting product comprises deep maroonlumps easily comminuted to form granules of a non-dusting color basesuitable for melting into appropriate lipstick base to form a gooddispersion possessing great tinctorial power.

Example 3 A one-gallon porcelain pebble mill is charged with grams ofRhodamine B Benzoated Lake (M: Fig. 40, page 387) and 1600 grams of aliquid grinding medium consisting of 30% denatured ethanol and 70% waterby weight. This is mixed well and to the mixture isv added 150 grams ofcetyl alcohol fine shavings. About 7 lbs. of #00 French flint pebblesare added. After milling for about 45 hours, the mill is discharged andrinsed out with water. The product and wash liquid are collected,filtered,.washed and dried at 120 F. after which the filter cake ispulverized to produce fine non-dusting granules used for the coloring oflipstick base. The filtrate was recovered and used as the liquidgrinding medium for another batch of a similar product.

Example 4 A one-gallon porcelain pebble mill is charged with 250 gramsof Phthalocyanine Green (M: Fig. 144, page 439) and 1500 grams of aliquid grinding medium comprising 450 grams of acetone and 1050 grams ofwater, resulting in a liquid medium consisting of about 30% acetone and70% water by weight. This is well mixed and to the mixture is then added250 grams of chlorinated 'diphenyl, such as is marketed under the tradename Arochlor #5460. About 7 lbs. of #00French flint pebbles are addedand milling is carriedout for approximately 40 hours. The mill is thendischarged and rinsed out with water. The product and wash liquid arecollected and filtered. The filter cake is washed, dried and pulverized.One obtainsabout 485 grams of a bright green powdered wax product.

As indicated hereinbefore, the amount of liquid grinding medium employedin the process is selected to provide a consistency suitable for optimummilling operation. As can be seen, wide variations in the amount ofliquid used is possible, depending upon the amount of solids to bemilled, the type of milling employed and the types of solid organicwaxes and pigment to be blended into a wax color master batch.

The amount of pigment used in the process, and therefore present in thefinal wax color master batch, may

vary from as little as about 1% to as high as approximately 95%'byweight, depending on the end use. For most purposes as a solid organicwax color master batch, a range of approximately 30% to 70% pigment byweight to the total weight of the color master batch is preferred.

It is in some cases advantageous to use additional materials in themilling operation to overcome certain difii culties inherent in thesolids being milled, whether in the solid organic wax or in the pigment.Thus, where the solids are acid or alkaline to such extent that theacidity or alkalinity might adversely affect the quality of the finalproduct, or might seriously corrode the milling equipment, one mayovercome this diflicutly by adding suitable buffering or neutralizingagents which are water soluble and thus capable of being easily removedduring the washing operations.

It is here pointed out that one may by the process of this inventionmake pigmented solid organic wax color batches with a mixture ofpigments, in lieu of the single pigment of the above examples, and/orwith a mixture of solid organic waxes rather than a single solid organicwax, in order to obtain desired properties in the pig mented solidorganic wax color master batch not obtainable with a single pigmentand/or with a single solid organic wax.

The terms color value and chromaticity as used hereinabove and in theclaims, are terms well known in the art and are employed substantiallyas described and discussed in Handbook of Colorimetry by A. C. Hardy,published by the Technology Press.

What is claimed is:

1. A process for dispersing pigment in a solid organic wax whichcomprises milling pigment and solid organic Wax in a liquid grindingmedium comprising water and a liquid organic water-miscible solvent inwhich the solid organic wax is at least partially soluble, the water andsolvent being present throughout the milling operation in suchproportions that the liquid grinding medium does not dissolve asubstantial amount of the solid organic wax and does not cause asubstantial agglomeration of the solid organic wax, the liquid grindingmedium being present at all times in such amounts as to give a fluidityto the mixture which permits effective milling action, continuing themilling action until a dispersion of pigment in solid organic wax isobtained, and thereafter separating the solid portion from the liquidportion of the milled mixture.

2. The process of claim 1 wherein the pigment and the solid organic waxare each admixed with the liquid grinding medium in particulate form,wherein the solid organic wax particles are cuased to becomepigment-receptive by action of the liquid grinding'medium thereon andwherein the milling action produces impinging contact of particles withpigment-receptive solid organic wax particles.

3. The process of claim 1 wherein the solid organic wax is selected froma class consisting of beeswax, Chinese wax, candelilla wax, carnaubawax, Iapanwax, montan wax, ozocerite wax, ceresin wax, parafiin wax,spermaceti wax, high molecular weight fatty acids and halogenatedaromatic compounds, chlorinated diphenyls and chlori nated naphthalenes.

4. A solid organic wax color master batch produced by the process ofclaim 1 wherein the amount of pig ment is within a range of 30% to ofthe total weight of the color master batch.

5. A solid organic wax color master batch produced by the process ofclaim 1 consisting essentially of pigmented solid organic wax in theform of free-flowing particles, said particles being readily dispersiblein a solid or liquid miscible with the wax to yield a uniform dispersionof pigment in the extended wax base.

6. A solid organic wax color master batch consisting essentially ofpigmented solid organic wax in the form of free-flowing particlespossessing a chromaticity not substantiallyless than the pigment portionthereof.

7. A solid lipstick color master batch comprising a solid organic waxinto which a pigment has been dispersed by the process of claim 1.

8. The solid lipstick color master batch of claim 7 wherein the wax isselected from a class consisting of cetyl alcohol and stearic acid.

9. The solid lipstick color master batch of claim 7 wherein the wax iscetyl alcohol.

10. A method of producing a solid organic wax color master batch whichcomprises milling pigment and solid organic wax in a liquid grindingmedium comprising water and a liquid organic water-miscible solvent, thewater and solvent being present in such proportions that the liquidgrinding medium does not dissolve a substantial amount of the solidorganic wax, the liquid grinding medium being present in such amounts astogive a fluidity to the mixture which permits effective milling action,continuing the milling action until a dispersion of pigment in solidorganic wax is obtained, separating the solid portion from the liquidportion of the milled mixture, and then washing, drying and pulverizingthe said solid portion to produce a pigmented solid organic wax colormaster batch.

11. The process of claim 10 wherein the pigment and the solid organicwax are each in particulate form at the beginning of the millingoperation.

12. The process of claim 10 wherein the pigment and the solid organicwax are each in particulate form at the start of the milling operationand wherein the wax retains its particulate form throughout theoperation.

13.- The process of claim 10 wherein the solid organic wax is cetylalcohol.

14. The process of claim 10 wherein the solid organic wax is stearicacid.

15. The process of claim 10 wherein the solid organic was is paraflin.

16. The process of claim 10 wherein the solid organic wax is chlorinateddiphenyl.

Hauser Dec. 16, 1941 Vesce Aug. 18, 1953

6. THE PROCESS OF TREATING ANIMAL BRAINS WHICH COMESSENTIALLY OFPIGMENTED SOLID ORGANIC WAS IN THE FORM OF FREE-FLOWING PARTICLESPOSSESSING A CHROMATICITY NOT SUBSTANTIALLY LESS THAN THE PIGMENTPORTION THEREOF